The present invention relates to apparatus for counting the number of elastic rings such as belts, rubber bands and O-rings.
In the past, in a production line for making belts, for instance, the final steps of counting the number of belts, bundling a specified number of belts together, and packing the bundle were mostly made manually by workers. In particular, counting of the belts was made by workers by actually counting them one by one.
For O-rings, one of the aforementioned types of elastic rings, apparatus has been proposed which automatically aligns a random number of O-rings in a pile and feeds them one at a time to a counter. Hence use of such a feeder may allow relatively easy and accurate counting of O-rings and the like.
Feeders of the above kind are of two types: a single spindle system wherein O-rings are aligned by sequentially guiding them into a spiral groove on a single screw, and a two spindle system wherein O-rings are aligned by running the O-rings over two screws.
One example of the single spindle type O-ring feeder is the apparatus described in Japanese Patent Publication No. SHO56-48412. This apparatus comprises a main screw onto which O-rings are loosely inserted, a plurality of driving screws which rotatably support the main screw and transmit turning force to the main screw, and a claw which slidably contacts the spiral ridge on one side of the main screw to drop an O-ring into the spiral groove. The apparatus is arranged to rotate the main screw, sequentially drop O-rings fed to one side (the claw side) of the main screw into the spiral groove, and deliver the O-rings to the other end of the main screw.
One example of the two spindle type O-ring feeder is the apparatus described in Japanese Provisional Publication No. SHO60-15314. The apparatus is provided with two spaced and rotatably mounted screws each having a spiral groove in the top end portion, and a shifting means for moving one screw towards the other screw. The apparatus is arranged to run a large number of O-rings around the non-spiral-groove portions of both screws, rotate one screw, align the O-rings, sequentially drop the O-rings into the spiral grooves, and deliver the O-rings from the top end.
The aforementioned conventional counting operation of belts by workers, however, is time-consuming and prone to miscounting. Furthermore, it hinders automatization of the production line for labor saving objectives and is a bottleneck in cost reduction efforts.
On the other hand, when the aforementioned single spindle type O-ring feeder is used to feed belts having a size greater than O-rings, the belts will interfere with the driving screws for the main screw and prevent feeding. Moreover, because the claw is fixed, a belt may be caught and damaged between the claw and the spiral ridge of the main screw. In particular, when belts are fed into the apparatus in a condition where they cross or overlap one another, it is almost impossible for the claw to drop belts properly into the spiral groove. Furthermore, there are problems due to a complex driving mechanism of the main screw and a high production cost.
The aforementioned two spindle type O-ring feeder may be used to feed belts. However, since the distance between the two screws is fixed beforehand, the apparatus is not capable of feeding belts of different sizes. Moreover, the minimum distance between the screws is structurally limited, and therefore the apparatus may not be used for belts of smaller sizes. Furthermore, because belts or the like are set around the two screws, setting by a worker is not easy, and belts will eventually remain between parallel grooves of the screws, requiring the worker to remove the belts.
The present invention has as its general object to avoid the aforementioned problems, and is intended to provide a counter for elastic rings which automatically and accurately counts elastic rings such as belts, and contributes to labor saving and cost reduction of products, is simple in structure, and counts elastic rings of different sizes.